The present invention relates to a zoom lens and a camera having the zoom lens, and in particular, to a zoom lens having a magnification ratio of about 2.5 to 4 suitable for an electronic still camera or a video camera employing a solid state image sensor such as CCD.
In recent years, there has been development of rapid strides of a software handling image data, together with technical advancement and spread of a personal computer, and there is a growing demand for an electronic still camera which is used to input images in a personal computer.
As a zoom lens for a solid state image sensor, there has been disclosed a zoom lens of a three-group structure type or of a four-group structure type, wherein a zoom lens for a video camera tends to be of a high magnification ratio, and a zoom lens of a four-group structure type is widely used for the video camera, while as a zoom lens for an electronic still camera, those meeting high resolution and high image quality are demanded, and many of them have a magnification ratio, namely the ratio of a focal length at the telephoto end position to that at the wide angle end position, of about 3, and a zoom lens of a three-group structure type has been disclosed as one having the magnification ratio of about 3.
A zoom lens for a solid state image sensor having a magnification ratio-of about 3has been disclosed in each of Japanese TOKKAIHEI Nos. 10-133115, 10-39214 and 10-104518.
However, in these conventional examples, there have been problems that distortion at the wide angle end position is -5% or more (less?), or a field angle at the wide angle end position is small although distortion is small, and a total length of a lens is great.